Local Limits Evaluation. Genet Belete Oregon DEQ Pretreatment Program

Transcription

1 Evaluation Genet Belete Oregon DEQ Pretreatment Program

2 Evaluation What does Oregon DEQ expect from technical evaluation of local limits?

3 Report Federal and State Requirements 40 CFR Parts 403.8(4) - The POTW shall develop local limits as required in 403.5(c)(1) Oregon DEQ permit - The permittee must perform a technical evaluation of the need to revise local limits within 18 months after permit re-issuance unless the Department authorizes or requires, in writing, an alternate time frame.

4 EPA Guidance document for Local Limits analyses EPA Local Limits Development Guidance and Appendices, July 2004

5 LL considerations for DEQ approval What are the expectations? I. Sampling and analysis plan

6 LL considerations for DEQ approval II. Technical evaluation of local limits.

7 I. Sampling and analysis plan Objective- The need for the sample plan Background- Information on current MAHL, MAIL, Local Limits and changes to POTW process and service area Pollutants for which sampling will be conducted

8 I. Sampling and analysis plan Data requirement for- Influent Pollutant loading Removal efficiencies Inhibition thresholds Industrial loading Sludge loadings Residential and commercial loadings

9 I. Sampling and analysis plan Sampling locations,(at the POTW, collection system or IU) Sampling methods (grab vs. composite, sludge) Sample frequencies (initial LL study or ongoing evaluation) Sample monitoring conditions

10 I. Sampling and analysis plan Analytical methods Flow data -Total POTW flow -From uncontrolled sources -From controlled sources (SIUs) -Sludge to digester -Sludge to Disposal Sample collection time line

11 I. Sampling and analysis plan Documentation of Sampling and analytical data - Field measurement records - Chain of custody - Lab reports Evaluation of analytical data - QA/QC

12 II. Technical Evaluation of Local Limits What s needed in the local limits report? 1. Background information needed for LL study - POTW s population and design - Loadings (inf., eff., and sludge) - Operational and compliance history - IU flow and loadings - State WQ standards and permit limits

13 II. Technical Evaluation of Local Limits 2. POCs Determination - EPA s 15 POCs - POCs in last LL vs. proposed - Added new POCs, why? - Removed POCs, why? - Discussion of total toxic organics

14 II. Technical Evaluation of Local Limits 3. Data collection- - Same time frame - From POTWs, uncontrolled and Controlled sources - Background ambient monitoring - Mixing Zone information - Hauled waste data (if applicable)

15 II. Technical Evaluation of Local Limits 4. MAHL determining Criteria discussion - Permit limits and/or WQ standards - Process inhibition & sludge disposal options - Other specific prohibitions per 40 CFR Part 403.5(b)

16 II. Technical Evaluation of Local Limits 5. MAHL analysis - Removal efficiency analysis - AHL calculation for each criterion (inhibition, WQ std, biosolids) - Discussion of data outliers and use of literature values, if applicable

17 II. Technical Evaluation of Local Limits 6. MAIL analysis - Uncontrolled sources (domestic, non regulated commercial, stormwater, I&I ) - Growth allowance and safety factor - Hauled Waste (if accepted)

18 II. Technical Evaluation of Local Limits 7. Local Limits allocation - Methods of allocation, uniform conc., IU contributory flow based, case by case, or mass proportion method. - If contributory flow or case by case allocation, identify IUs and associated IU flow.

19 II. Technical Evaluation of Local Limits Local Limits allocation cont. - Discuss local limits for Non-conventional POCs and Total Toxic Organics - List numeric limits for all POCs - Discuss proposal to add or remove POCs

20 II. Technical Evaluation of Local Limits 8. Implementation -How is the LL incorporated to the POTW s legal authority? -Is the proposed local limit protective of the POTW s treatment system, workers health and Water Quality?

21 Overall LL approval process In Summary Contact PP Coordinator ahead of time Submit Sampling Plan for review Submit the LL report for preliminary review/approval Public notice, if substantial modification Final DEQ approval

22 Overall LL approval process DEQ s Incorporation of the approved LL into the permit If the POTW s NPDES/WPCF permit is active, LL will be incorporated into the permit via Permit Action Letter per 40 CFR (g)

23 Overall LL approval process Incorporation of the approved LL into the permit If the NPDES/WPCF permit is on administrative extension, DEQ will issue an approval letter and; local limits will be incorporated into the permit during next permit renewal.

24 Local Limits Evaluation Questions?